In recent years, LEDs having a long life span and low power consumption have become widespread as backlights for liquid crystal display devices and light sources for illumination devices. Such light sources obtain a desired emission color with LEDs having a plurality of different emission colors being combined and with single-color LEDs and phosphors being combined. For example, a white LED is generally configured with a blue LED and a phosphor being combined. In such a white LED, white light is obtained by a mixed color of blue light that is emitted from a blue LED chip and light that is emitted due to the phosphor being excited by this blue light.
For example, PTL 1 discloses a technology in which a blue LED chip and a YAG phosphor that is excited by light emitted from the blue LED chip and emits yellow fluorescence are used, and blue light emitted from the blue LED chip and yellow light emitted from the YAG phosphor serve as a mixed color for white light to be output.
Furthermore, although illumination light of a desired color may be obtained by mixing light from LEDs having a plurality of different emission colors, there are light-emitting devices that have a function to adjust the color of illumination light by adjusting the emission color of each LED.